The present invention pertains to portable apparatus for making snow.
This snow is generally made artificially for ski slopes by the use of stationary equipment or by the use of moveable or portable equipment. Examples of stationary type equipment for producing snow are snow making towers, such as disclosed in my U.S. Pat. No. 3,822,825 and U.S. Pat. No. 3,952,949. Other stationary snow producing apparatus consist of relatively large blower fans mounted on top of a relatively short pole or support and having a central water discharge in front of the fan.
Obviously, a problem existing with stationary snow making apparatus is that due to wind and other weather conditions, such as temperature, sun exposure, etc., areas of the ski slope to be surfaced by stationary equipment may not be adequately covered with snow and the only effective way to compensate for this is to bring in portable snow making units to produce smaller quantities of snow in the sparse areas.
The portable type snow making apparatus presently available generally consist of two types. One type is generically referred to as a snow gun and the other may be referred to as a fan blower unit.
The snow gun type of portable unit generally consists of a relatively short structure which may be readily handled and moved about by an individual and is supplied with compressed air and water which is delivered to a mixing chamber in the gun wherein the compressed air and water under pressure are mixed and a nucleated water spray is ejected from the mixing chamber into the ambient freezing atmosphere. Examples of such snow guns are shown in U.S. Pat. No. 3,010,660; 3,298,612 and 3,464,625.
The problems encountered with portable snow guns is that, while they are very mobile, they can not efficiently produce snow of adequate quality in large enough quantities. They are also prone to easily freeze up at the discharge nozzle thereby rendering them ineffective and tend to collect large quantities of ice on the exterior thereof rendering them inmobile and ineffective. These same shortcomings also prevent the snow guns from being constructed with any adequate height above ground. All of these shortcomings taken together prevent snow guns from being an effective large quantity producer of good quality snow and also prevent them from providing an adequately wide area of snow distribution over the ski slope in front of the snow gun.
The blower type portable ground unit consists of a large fan driven by a relatively large motor (15 HP) with a water nucleator positioned in front of the fan. The fan blower unit also carries an air compressor with it (another 5 HP) and the air supplied under pressure from this compressor is mixed with water supplied to the unit under pressure in an internal mixing chamber and then this mixture is ejected in a form of a nucleated spray in front of the fan. Additional water discharge nozzles are also circumferentially positioned about the fan and this additional water supply may be regulated depending upon the ambient temperatures.
While this blower type unit is indicated as being portable, in reality it is quite heavy and most probably weighs in the area of 600 lbs. It is therefore moved about the ski slope with the aid of a motorized vehicle.
For safety reasons, the fan blade is enclosed within a cage provided with a cowling for flying ice and the cage can readily collect ice which restricts the efficiency of the operation of the machine.
Also, in view of the fact that this portable unit is positioned at ground level, the ground surface distribution is limited. Furthermore, in view of the fact that the water nucleation is created in an internal chamber wherein the water under pressure and the air under pressure are mixed, the maximum usable water pressure for nucleation is limited to the air pressure value then utilized since a greater water pressure would cause the water to back down the air supply tube.
In addition, these fan blower type systems are comprised of many moveable parts which are of course subject to breakage and continual maintenance and other parts of the machinery are also subject to rust. Accordingly, after the ski season is over, such an expensive unit will normally be stored indoors in order to minimize damage due to exposure to the elements. In regard to cost, such units are also quite expensive in view of their large and complex nature. In addition, they also require a considerable amount of energy consumption per minute for operation, about 35 HP per minute.
Such blower units are also limited in their production of snow at warmer temperatures. For example, if such a blower system is operated at an ambient temperature of 28 degrees F it will be limited to a maximum useable water consumption rate which is probably in the area of 35 gals./min. Larger rates for production of snow would certainly be desirable. They also require considerable adjustment of the circumferentially positioned water nozzles for changing temperature and humidity conditions.